Hot tub startup in winter
Winter hot tub start-up
Our new spas are kept around 70 degrees in our store and warehouse. Due to the efficient perimeter insulation systems, interior components, pumps, heater and electronics, will normally stay above freezing in an empty spa for 24 hours or so in sub freezing conditions. (That may be less time in very sub freezing or windy conditions.) After about 24 hours sitting outside, still empty and not turned on, those components will freeze. Normally this is not a problem because the factory blows 99+% of the test water out of the pumps, pipes, and equipment. However…..
If there is as little as 1 oz of water sitting in a pump, that water will freeze and will prevent the pump from starting. No pump = no heat.
During these months it is best to get the electrical connection done the same day we deliver the spa. If that is not possible and the spa sits for several days in freezing weather it’s very possible that 1 oz of ice that may be in the pump will prevent the spa from starting up once connected.
(Except for short periods of testing, a hot tub should never be powered up until the water is all the way up to the normal operating level. In most hot tubs that is above the top jets and just below the pillows)
To avoid this situation either get it running the same day as delivery or prevent the temperature inside the cabinet from dropping below freezing. This can be done in most cases by placing a very small cube heater inside the cabinet positioned so nothing is directly in front of the heater, it won’t melt anything and with the cabinet panels all in place to hold the heat in. It’s also possible to place a small cube heater inside the actual empty spa pointing as far away from any surfaces as possible and with the hard cover on. The small amount of heat will flow through the spa shell into the insulated airspace around the spa and keep everything from freezing.
If none of the safeguards above have been done and the spa has been sitting in sub freezing temperatures for more than 24 hours proceed as follows.
After your electrician has finished and prior to filling the spa, you should turn the breaker on long enough, (30 to 60 seconds) for the system to initialize and for the pump to start running. If you hear a hum or buzz, (like a motor that can’t spin) that is an indication that the pump has ice inside it and it’s not spinning. There is nothing wrong with the spa.
In this case shut the breaker off immediately and place a cube heater inside the cabinet as described above. After 4 to 8 hours of heating the airspace and with the spa still empty, turn the breaker on again and see if the motor spins freely now or just hums. If you can hear the motor running, (sometimes you can even hear a little water sloshing) turn the breaker off, fill the spa through the filter hole to flood the pump(s) and push all the air out of the lines. Once it's completely full to the normal operating level, turn the breaker on. If everything has thawed out, the pump should start moving water and heating the spa.
Best practice is to get the spa up and running on the day of delivery.
This information does not apply to full foamed spas like Hot Spring or Marquis.